1. Field of the Invention
The present invention relates to a voice and video communication apparatus capable of communicating the voice information, and the video information such as animation or still image.
2. Related Background Art
Conventionally, there was provided a telephone capable of discriminating, for example, between reception calls from the extension and those from the outside line, by changing the timbre or intermission intervals of reception sound for the telephone.
On the other hand, there was a disadvantage that when a TV telephone set capable of communicating both voice and video informations was connected to the telephone line and used together with a telephone set, it was difficult to discriminate between reception calls from the TV telephone and those from the telephone.
By the way, in ISDN, when the call is received, the communication attributes (transmission ability information factor, lower layer matching information factor, higher layer matching information factor) are notified in an equipment at the reception side. However, an operator at the reception side was not informed of whether the reception call was intended for voice alone or voice with image, for example, based on those communication attributes.
Thus in a communication apparatus capable of communicating the voice and video, there was conventionally a problem that as an operator was not informed of the discrimination between a reception call from telephone and that from TV telephone, an operator's indiscrete appearance might be transmitted to a partner with the TV telephone, if the operator responds to the reception call in the telephone mode irrespective of the TV telephone.
Recently, as the communication service with the ISDN line has been put to practical use, the AV (Audio Visual) service such as a TV telephone or a TV conference system which uses such digital lines comes to public notice, and the service rules for AV service, the protocol rules, and the multimedia multiplication frame structure regulations are publicized as, for example, the CCITT (International Telegraph and Telephone Consultative Committee) recommendation drafts H.320, H.242, H.221 and the like. The draft H.221 defines the coding allocation of BAS (Bit Allocation Signal) which is used for the frame structure and terminal ability exchange, the terminal mode switching, or the bit allocation indication in the AV service on a channel from 64 Kbps to 1,920 Kbps. The draft H.242 defines the protocol procedure between AV terminals, and the draft H.320 defines the system aspect of the entire AV service. The recommendation drafts in association with AGC (Audio Graphic Conference) are also examined successively.
The above drafts define a procedure for selecting a mutual communication with the highest ability between terminals, with the procedure such as a terminal ability exchange sequence with BAS between in-channels or a mode switching sequence, after the establishment of physical connection and synchronization for end-to-end.
Thus, since a conventional terminal responds automatically to a reception call accepted, in accordance with the terminal ability, the video communication ability of an operator's terminal is notified in a partner's terminal undesirable for the mutual communication of video if it is provided. Thereby, there was a disadvantage that a video was automatically transmitted also to a partner's terminal which did not desire to communicate with the video.
In this way, in a conventional TV telephone set capable of communicating the voice and video, the protection of privacy of a terminal user was a consideration.